Electrochemical estimation of intergranular corrosion susceptibility on aluminum alloys

Abstract

A new anodic dissolution method for rapid estimation of intergranular corrosion susceptibility of aluminum alloys has been proposed. The validity of the method is discussed in terms of electrochemical measurements and immersion tests on Al-Mg-Si and Al-Mg alloys. The precipitation heat treated alloys are susceptible to intergranular corrosion at the pit bottom. The probability of this type of corrosion is easily estimated by surface observation of the alloys after anodic dissolution test in deaerated 1N AlCl₃ solution at the current density of 100 μA/cm² or 1mA/cm².